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Kraaf wrote:And while making aero-predictions is a bit like astrology, having a flush tire-rim interface does appear to be a smart thing to do. It seems to be a key factor in gettting low-profile rims reasonably aerodynamic.

Based on the evolution of rim shapes and recent tests, I'd wager that these rims have low drag and good cross-wind stability performance... as in the best of aluminum rims... with the XC279 also in the running.

why hit the quote button when you could just hit the reply button? Specially when you replay had nothing to do with my quote.....

There is a lot you could read about on wide rims.1) they change the shape of the tire making for better contact patch for cornering. Also the tire holds its shape better so no noddling at lower pressures.2) larger air volume so you can run lower pressure allowing better ride3) the rim is about the same width as the tire side wall which in theory improves air flow off the tire and arounf the rim. Idea it is better than the light bulb shape 23mm tires have on 19mm wide rims.4) wider rims are stiffer allowing a lower spoke count (but the extra width means more material so a bit heavier)

The reason there are more and more wide rims is because people realise they like them. End of story

I would like to see a Pacenti tubular rim that would be similar to the SL23 in terms of general shape.

But I'm not really positive a wide tubular rim has the same purpose as a clincher rim. I would see the tubular version not as wide, to allow for road use mainly. Or the bead shape would have to be road oriented.NOT like the Major Tom. If I compare with the Velocity shape, lots of people like the A23 clincher, but the same shape in tubular is not really mad efor 23 mm tire. You have to use 25-28 mm tires for a perfect bond and shape.We saw bulky tubular rims appear on the market, mostly to win some wind tunnel side wind drag contests (IMHO).The comfort issue is not relevant in regards to rim width with a tubular rim. Different story with clincher rims and tires...The shape of the rims would act as a deflector, and at the same time, would mold perfectly with the shape of the tubular tire glued, and inserted in the bead.With an alloy rim, I'd be curious to know what rim shape would be the optimum, for weight savings, strenght, some aero benefits, and best for road use, mainly with some 22-24mm tubulars.

The SL23 shure would be a nice template to start with. If we transfer te Kinlin comparable weights, maybe Pacenti can come close to 400-415 g per rim. Would be super. I'd certainly buy a pair.

LouisN wrote:I would like to see a Pacenti tubular rim that would be similar to the SL23 in terms of general shape.... The SL23 shure would be a nice template to start with. Would be super. I'd certainly buy a pair.

The Pacenti SL23 rim actually has a 24mm outside width. So, I wonder how the number 23 got snuck into the name of the rim. Also, if the outside width is 24mm, then the rim is optimised for a 24mm clincher tire. And there is only 23mm and 25mm tires available.